Throughout the world, potable water and gas distribution systems use different types of pipes, valves, and fittings. Most systems, even with their variations, typically include a water or gas flowmeter connected into the system, for example, at a residence or other premises. The flowmeter measures the fluid flow over time, which is then used to bill the premises owner its use of water and/or gas consumed at the premises. There are many different types of pipes, valves, and fittings that may be incorporated in a water or gas distribution system, and different water or gas metering technologies may be used to measure the consumption of water and/or gas depending on the system. Each different type of water or gas distribution system has its own pros and cons and the choice made for any particular flowmeter at a premises is often based on the flowmeter price, flow accuracy, manufacturing process, installation ease, maintenance requirements, and size of its components, relative pipe sizes and placement.
Usually a gas or water distribution system at a premises includes a dedicated fluid flow metering device, which typically operates in conjunction with a manually operated shut-off valve that is located before or upstream of the fluid flow metering device in order to allow a technician to shut off fluid flow and maintain and/or replace the fluid flow metering device when necessary. There are many different examples of gas and water mains that incorporate a shut-off valve adjacent a fluid flow metering device. Usually, a household premises includes either a ball valve or a gate valve in the main gas or water line. Sometimes a yoke box holds a shut-off valve and/or water or gas flowmeter and may incorporate an optional, electronic meter reading iron lid that is removed to access the shut-off valve and/or flowmeter. A domestic water distribution system supply water to appliances such as toilets, faucets, water heaters, and similar devices, and a natural gas distribution system may include a gas main having a shut-off valve and gas flowmeter adjacent or on the house and the gas main connected that branch out into smaller pipe to supply gas appliances such as a grill, lights, pool heater, or similar components. There are problems associated with these more conventional gas and water distribution systems such as size constraints for various valves and fluid flowmeters, unacceptable flowmeter accuracy, and pressure drops that occur in the gas or water distribution system that affect accurate fluid flow metering.
Commonly assigned U.S. Pat. No. 6,923,074 discloses a ball valve with a flow-rate gauge incorporated directly into the ball valve. The ball portion of the ball valve includes a calibrated borehole or orifice and two positionable pressure ports placed before and after the ball respectively, to provide measurements indicative of the flow-rate of the fluid that passes through the ball valve. This ball valve is usually limited to water use. Although it is effective to measure fluid flow at typically higher water flow rates, it has some reduced accuracy at lower water flow rates.
In the past six years, the gas and water metering industry has improved the affordability, performance, and accuracy of ultrasonic flowmeters that use transit time measurements or Doppler Effect measurements. These ultrasonic flowmeters measure the amount of time required for an ultrasonic signal, e.g., an emitted “ping” to pass between two or more fixed points inside the flowmeter. When the ultrasonic flowmeters are calibrated properly for gas and water, they can be used to measure both fluid media. Ultrasonic flowmeters typically incorporate one or more ultrasonic transducers to emit ultrasonic sound waves through the fluid to determine the velocity of the fluid. Because the cross-sectional area of the flowmeter body is a fixed and a known value, when the velocity of the fluid is detected, the volume of fluid passing through the flowmeter may be calculated to a very high accuracy. Also, because fluid density changes with temperature, most ultrasonic flowmeters measure the fluid temperature as a component of the volume calculation and determine fluid flow based on temperature as a variable. When used with ball valves, the ultrasonic flowmeters are connected directly to an existing ball valve or connected into the gas or water pipe to which the ball valve is connected. This may increase the ball valve and its closely connected ultrasonic flowmeter footprint, i.e., make the combination too large for a workable solution, making the flowmeters and valves difficult to install, maintain, and replace.